1. Field of the Invention
The present invention relates to a terminal connection structure of a motor incorporated within a compressor, such as a motor-driven compressor or a hybrid compressor, and more specifically, to a terminal connection structure for improving insulation properties of the terminal connection portion, facilitating manufacture of the compressor, and reducing the compressor's size.
2. Description of Related Art
In a motor incorporated within a compressor, a stator of the motor is disposed in a compressor body. To supply power to the stator, external feed terminals are provided on an outer surface, such as a radial or side surface, of the compressor body, and wire-side terminals, which are provided at the ends of wires connected to the stator, are connected to the external feed terminals. Because a high-voltage motor is used as the motor incorporated within a compressor, such as one used for an air conditioning system for vehicles, it is desirable from the viewpoint of safety to insulate between the terminals and terminal connection portion and the compressor body, thereby achieving a structure without the risk or with a reduced risk of an electrical short. In particular, because a motor incorporated within a compressor used for an air conditioning system for vehicles compresses refrigerant, which may be highly conductive, it is desirable to ensure that the refrigerant does not become the source of an electrical short.
In a known technology, the above-described insulation properties have been ensured by providing sufficient separation between the terminal connection portion and the compressor body. Nevertheless, because providing sufficient separation between the terminal connection portion and the compressor body may impede efforts to reduce compressor size, a method for obtaining the insulation properties by injecting a resin into the terminal connection portion also has been attempted. Further, Japanese Patent Application No. JP-A-2001-182655, the disclosure of which is incorporated herein by reference, describes a structure wherein a ceramic insulator is interposed between the terminal connection portion and the compressor body, the terminal connection portion is covered with a resin tube, and the resin tube is connected to the ceramic insulator.
In the structure in which a separation is created between a terminal connection portion and a compressor body, however, it becomes difficult to reduce the compressor's size, as described above. Further, in the structure in which a resin is injected into a terminal connection portion, time for injection of the resin and for curing of the resin is required, and it becomes difficult to improve the productivity and the assembling performance. Moreover, in the structure disclosed in Japanese Patent Application No. JP-A-2001-182655, because a terminal connection portion may include a ceramic insulator and a resin tube, it may be difficult to achieve an effective sealing of the connection portion due to a difference in thermal expansion coefficients between the insulator and tube materials. In addition, although a heat-shrink, resin tube may be used, if non-uniform shrinkage occurs, it also may be difficult to achieve an effective sealing of the connection portion.